The ECG in Chronic Obstructive Pulmonary Disease

Mechanisms

ECG changes occur in COPD due to:

The presence of hyperexpanded emphysematous lungs within the chest.

The long-term effects of hypoxic pulmonary vasoconstriction upon the right side of the heart, causing pulmonary hypertension and subsequent right atrial and right ventricular hypertrophy (i.e. cor pulmonale).

Effects of Emphysema on the Heart

Lung hyperexpansion causes external compression of the heart and lowering of the diaphragms, with consequent elongation and vertical orientation of the heart.

Due to its fixed attachments to the great vessels, the heart undergoes clockwise rotation in the transverse plane, with movement of the right ventricle anteriorly and displacement of the left ventricle posteriorly.

The presence of increased air between the heart and recording electrodes has a dampening effect, leading to reduced amplitude of the QRS complexes.

Clockwise rotation of the heart with delayed R/S transition point in the precordial leads +/- persistent S wave in V6. There may be complete absence of R waves in leads V1-3 (the “SV1-SV2-SV3″ pattern).

With development of cor pulmonale, the following additional changes are seen:

About Edward Burns

Ed Burns is an Emergency Physician working in Prehospital & Retrieval Medicine in Sydney, Australia. He has a passion for ECG interpretation and medical education. Ed is the force behind the LITFL ECG library | + Edward Burns | @edjamesburns